A map where you have a workerr that can only build towers (maybe more workers after some turns) you have to kill enemies before they reach a Tc at the end of the map
If they reach the tc the game is over

You can play solo and win by killing all the "waves" of enemies or you can play multiplayer with every player in a separate route.
The last one to remain alive is the winner

Enemies should progressively becoming stronger (you might make this by giving every turn a +1 bonus to something for all the units of the ai players)

awesome idea (the campaign map style):
i imagine a map
- with a few workers and wagons to easily move them
- some initial enemy that is disabled behind "fog of war" part of the map
- task is to build towers/fortresses/walls and other similar buildings (can not build buldings with production ability)
- the player has only 1 TC and that is disabled (can not build anything)
- the game starts the waves by triggering on eg. 5th turn, 10th turn, 15th turn and so on.

So here is the first plan:
Enemy arrives every 5 th turn
Player gain a worker every 5th turn.
Instead of a Tc the player has a disabled blacksmith
first wave: 5 swordsman
second wave: 10 swordsmam
third wave: 10 swordsman, 5skirmisher
4 th: 15 swordsman, 10 skirmisher
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.
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